The NHL awarded Seattle an expansion franchise Tuesday, but before a team comes to the Emerald City, construction on a new arena at Seattle Center will needs to be completed.

The timeline has been a question for months. Arena investors initially hoped for a 2020 start for a hockey team, but the NHL said concerns about arena construction prompted them to push a start date back.

“The lack of certainty led us to believe that making the start of the 2020-21 season would be speculative at best and unlikely at worst,” NHL Commissioner Gary Bettman said.

Here’s where the timeline stands as of now:

December 5, 2018 – Groundbreaking begins on the Seattle Center arena construction.

2018-21 – NHL Seattle plans to develop a 180,000-square foot headquarters and training facility at Northgate, although the group has not announced when it will break ground on the project.

March or April 2021 – NHL Seattle President Tod Leiweke expects the arena to be ready and open in time for the Seattle Storm schedule.

WATCH: Renderings of new arena at Seattle Center

2021-22 – An NHL team begins play in the newly-constructed Seattle Center arena.

Other items that have yet to be determined include a team name, colors, and when season ticket holders will see their seats.